Search for dissertations about: "pulse width modulation"

Showing result 1 - 5 of 39 swedish dissertations containing the words pulse width modulation.

  2. 1. Pulse-Width Modulated RF Transmitters

    Author : Muhammad Fahim Ul Haque; Ted Johansson; Dake Liu; Qamar Ul Wahab; Franz Dielacher; Linköpings universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : The market for wireless portable devices has grown signicantly over the recent years.Wireless devices with ever-increased functionality require high rate data transmissionand reduced costs. READ MORE

  4. 2. Control and Analysis of Pulse-Modulated Systems

    Author : Stefan Almér; Ulf Jönsson; Gilead Tadmor; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Pulse-width modulation; Periodic systems; Stability analysis; Harmonic analysis; Lyapunov methods; Dynamic phasors; Harmonic transfer function; Switched mode power converters; Sampled data modeling; H-infinity synthesis; Optimization; systems theory; Optimeringslära; systemteori;

    Abstract : The thesis consists of an introduction and four appended papers. In the introduction we give an overview of pulse-modulated systems and provide a few examples of such systems. Furthermore, we introduce the so-called dynamic phasor model which is used as a basis for analysis in two of the appended papers. READ MORE

  5. 3. Modulation, efficiency and lifetime of two-level and multilevel converters for a hydropower application

    Author : Chengjun Tang; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pumped-storage hydropower; pulse width modulation; losses; modular multilevel converter; efficiency; variable speed; converter; lifetime; space vector modulation; thermal modelling; neutral point clamped converter;

    Abstract : Along with the integration of the renewable energy in the electrical grid, the pumped-storage hydropower has gained more and more attention due to its fast response and energy storage ability. To have a higher overall efficiency and more flexibility of the system, variable speed is preferred in the operation of the pumped-storage hydropower applications. READ MORE

  6. 4. On soft-switching isolated AC/DC converters without auxiliary circuit

    Author : Staffan Norrga; Stefan Östlund; Rik De Doncker; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; voltage source converter; cycloconverter; isolated converter; medium frequency transformer; soft switching; modulation; commutation; wind power; electric traction; Elkraftteknik; Electric power engineering; Elkraftteknik;

    Abstract : The thesis is concerned with a class of power electronic converter systems that permit bidirectional AC/DC conversion with galvanic separation of the AC and DC sides by a transformer operating at elevated frequency. The systems consist of a capacitively snubbered voltage source converter and a cycloconverter, separated by the mentioned transformer. READ MORE

  7. 5. Modeling and Control of Voltage Source Converters Connected to the Grid

    Author : Michael Lindgren; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; voltage source converter; switching frequency; pulse width modulation; IGBT valve; power electronics; small-signal; L-filter; LCL-filter; transfer function; line filter; active filtering; frequency response; sampling frequency;

    Abstract : This thesis deals with the modeling and control of pulse width modulated (PWM) voltage source converters connected to the grid. When voltage source converters are connected to the grid, the power quality and the dynamic performance are affected by the line filter connected between the converter and the grid, and by nonlinearities caused by the switching converter. READ MORE